Research On Speed Sensorless Variable Frequency Speed Control System Of Induction Motor

With the development of technology, AC variable speed to replace the DC speed is possible.Compared with DC speed control, high-performance vector control system has become a hotspot of the current development. Unable to install the encoder for special occasions, Speedsensor-less control strategy becomes a new research field of high-performance vector control.This article describes the basic theory of vector control, analysis of the mathematical modelof the three-phase induction motors in different coordinate systems, including the fluxequation, the voltage equation, and torque equation. On this basis, by coordinatetransformation, rotor field oriented vector control system is proposed. And there is a depthanalysis to speed sensor-less vector control system of key issues, parameter identification, andidentification of flux and speed estimate. For special occasions, static method of measuringthe mutual inductance is presented. On the basis of voltage model, the current model,improved flux identification method is presented. On the basis of estimating the speed in theopen loop, Model Reference Adaptive is presented.Verify the feasibility of the various modules and vector control system by MATLAB/SIMULINK, the flux recognition; improved speed estimation method is simulated. On thisbasis, based on the DSP28335speed sensor-less vector control system software and hardwareplatform is designed. The hardware mainly includes main circuit, drive circuit, the signalprocessing circuit, fault protection circuitry. The software mainly includes main program,interrupt program, parameter identification program. On the basis of software and hardwareplatform, the correctness of the software modules is verified through a step-by-step debugging.Observe and analyze each variable waveform through the LABVIEW. The results show thatactual motor control system has a good dynamic and static performance.